Existing adaptive cruise control (“ACC”) and forward collision warning (“FCW”) systems provide radar sensor solutions optionally supplemented by a forward-looking monochrome camera. Radar sensors work well for longitudinal distance and velocity measurements but may not be able to detect certain traffic situations that rely on precise and robust lateral tracking. For example, existing radar systems often cannot detect neighboring lane disturbances that can occur when a vehicle is overtaking other vehicle, such as semi-trucks, at low relative speeds. In particular, radar systems may see sporadic reflections in the driving neighboring lane due to the mass of the truck side and may not be able to maintain tracking of previously-seen vehicles. Existing radar systems also may not be able to provide proper reactions when a target vehicle in the same lane slows and turns sharply into another street (often referred to as “McDonald's turns”). For example, existing radar systems may unnecessarily decelerate the vehicle or provide warnings in this situation. Furthermore, many existing radar systems cannot properly detect “late” vehicles, such as when a vehicle abruptly cuts into a lane.
These situations may be mitigated to a certain degree by a camera that can provide information on lane position and vehicle detection. However, existing monochrome cameras need to see most of or the entire backside of a vehicle to detect the vehicle and can only track the vehicle when a majority of the vehicle back-side is within the camera's field of view (“FoV”). As a result, cameras are not able to fully eliminate all the above errors, especially for cut-in situations.